I have read many times that the C6 is lacking in gears for a truck. A 7,000-lb truck hauling up to 15,000-lbs needs more gears. Sometimes, apparently, a 3-speed automatic is not enough. So with the wide ratio gearset, 2.71:1, 1.55:1 and 1:1 gears, where do I need another gear? I can see needing...